Ammunition feed booster



i n mmm N m m MW v 0U A 7 EA 6 0 2 4 mr 3 4 a n .v w w lnlu 9A, F 6% m my 1945- J. E. CHAPMAN ETAL AMMUNITION FEED BOOSTER Filed Nov. 29, 1941Patented July 2, 1946 UNITED STATES PATENT osrlct:

James E. Chapman, Los Angeles, and George A. Busslere, Inglewood, GaliL.asslgnors to North American Aviation, Inc., Inglewood, CallL,acorporatlon of Delaware Application November 29,1941, Serial No. 30,958

'lClaims. I

The present invention relates generally to means or mechanism forboosting the feed of ammunition belts to machine guns, especiallythoseguns for which it is highly desirable to store large quantities ofammunition at a point substantially remote from the guns, and has forits primary object the provision of a mechanism which may be readilyregulated and adjusted so as to act solely in conjunction with theconventional ammunition feed ofthe gun in the ammunition feedingoperations, to thus avoid all danger of overfeeding, and at the sametime permit of manual feed of the ammunition belt at any time thisbecomes necessary or desirable.

It is well known that in the use of machine guns in airplanes it isdesirable, on account of limited space immediately adjacent the gun, tofeed thereto ammunition belts from a storage point some distance fromthe gun. It is also true that modern requirements for shells ofincreasing calibre have increased the weight of the ammunition belts andthe difficulties in properly feeding the same, from a remote point ofsupply or storage, to the gun. These factors have resulted inover-taxing the conventional ammunition feed of the gun, and it is forthis reason a major consideration of the present invention to provide anefficient means of boosting the feed of the ammunition at a pointbetweenammunition storage and the conventional feeding mechanis'm at thegun, which will efficiently assist the latter in its feeding operationsand effectively take care of the greater length of ammunition belts andtheir greater weight under modern demands.

A further object is the provision of an ammunition feed booster, of anelectrically operated character in connection with means eflective tosynchronize the boosting impulses thereof with the feeding operations ofthe conventional ammunition feed at the gun.

A still further object is the provision of a booster unit which will becompact, of small size, and capable of ready use at any one point, orseveral points, in the line of ammunition feed to the gun.

With the foregoing in mind, the invention will be now described indetail in reference to the accompanying drawing, forming a part of thisspecification, and in which,

Fig. 1 is a side view, illustrating the practical application of thebooster in connection with an ammunition belt.

Fig. 2 is a detail vertical longitudinal section taken substantiallycentrally through the booster. r

Fig. 3 is a diagram of the motor circuit of the booster controlled bythe firing key operation of 5 the gun. I

Referring now-particularly toFlgs. 1 and 2, the invention contemplatestheprovision of a booster unit in which a feed sprocket It, for anammunition belt A, which sprocket maybe sultably mounted in the feedline of the belt between the gun and an ammunition storage station, hasimparted. thereto, rotatable step by step. feed movements from a motorII. This motor is shown encased within the sprocket, the latter 16 beinghollow for thi purpose, andthe motor being supported at one end inconnection with-an end plate l2.

The plate l2 closes one end of the sprocket l0 and may form part of anysuitable support maingo taining the unit as a whole in the desiredposition for use. Plate l2 may also support an adjustabie member at isfor adjusting the brushes of the motor Ii to control its power output.

However, thi may be accomplished by control-' ling a rheostat 44 throughadjustable member iii, the object of such control being to so regulatethe power output of the motor substantially below that required forammunition feed so. that it will function only in connection with theoperation of the conventional ammunition feed of the gun. i

The motor may support rollers M or other anti-friction memberstherearound for the spacing and rotatable support of the sprocket l0,and

drives the latter through reduction gears l5 at the opposite internallytoothed end of the sprocket, and through a magnetically controlledclutch indicated at I6, 0 that when current is cut off from motor, ii,the sprocket is permitted to free wheel and allow manual manipulation orfeed of the ammunition for any reason, as for instance failure oi. thegun to fire through a defective shell. 1

The last mentioned end of the sprocket In carries a closed end piece llwhich has rotatable bearings l8 in an end frame It. This frame is andthe first mentioned end plate i2 may cooperate to support a shield 20along and spaced from the sprocket ill to hold the ammunition thesprocket, as best' seen in Fig. 1.

The end plate I! may have a socket 2| for reception of a current feedplug for supplying current to the motor,-and the magnetic clutch belt Ain properly meshed feeding relation with at 22 and a driving plate 40connected to be driven by the motor II, as suggested at 4|. The clutchplate l8, which floats between the plates 22 and 40, is mounted on shaft42 which also carries gear 43 of the reduction gearing ll. A spring 23tends to move the shaft 42 to the left in Fig. 2, thus tending todisengage the driven plate 16 from the driving plate 40. A magnetic coil46 is connected in parallel with the motor. When the coil 46 isenergized, the magnetic current attracts the driving plate 40, therebypulling the driven plate It from the brake plate 22 and against thedriving plate 40. When the circuit is broken, the magnetic attractionceases and the spring 23 is permitted to move the clutch plate I6 to abraking position against the brake plate 22. The braking action stopsrotation oi the gearing l by stopping rotation of the enmeshing gear 43.The said braking mechanism tends to prevent rotation of the sprocket II)when the motor circuit is broken. A hand piece 24 is provided at theouter end of the shaft 42, to manually shift the clutch plate I6 awayfrom the brake plate 22 so that the sprocket l0 may free wheel.

According to the diagram of Fig. 3, closure of the firing switch 25 inthe line 26 from a suitable source 21 of current and the firing solenoidof the gun, feeds current into the line 28 through the motor II toground, to thus operate the booster motor.

In the motor line 28 of Fig. 3, there is shown a knock-out switch 32,which is normally closed in operation. This switch is shown in Fig. 1 ascontrolled by an arm 35 normally held, in a position to maintain theswitch closed, by its contact with the ammunition belt A. When the endof the ammunition belt passes the switch 32, arm 35 drops and the switchopens to thus prevent further motor actuation of the sprocket. It iscontemplated such a switch arrangement may be used at a point in theammunition feed line, so that when it is opened there will remain only aportion of the ammunition belt that the con- .ventional feed of the gunis well able to take care of without assistance by the booster. Thisarrangement obviously need not be used except where there is possibilityof buckling of the ammunition belt.

The invention as shown and above described supplies a small, compactunit capable of installation in approximately the space normallyoccupied by the guide sprocket alone, as well as one which may bemanufactured as a standard ammunition feed booster for all installationswhere such a booster may be needed.

While we have illustrated and described what we now regard as thepreferred embodiment of our invention, the construction is, of course,subject to modifications without departing from the spirit and scope ofour invention. We, therefore, do not wish to restrict ourselves to theparticular form of construction illustrated and described, but desire toavail ourselves of all modifications th'at may fall within the scope ofthe appended claims.

1. An ammunition feed booster for machine I structed and arranged toresist rotation of the sprocket when the circuit is broken.

2. An ammunition feed booster for machine guns including a hollowsprocket, an electric motor within the hollow of the sprocket. gearingoperatively connecting the motor with the sprocket. a brake means, afloating clutch plate having braking, neutral andmotor-sprocket-connectlng positions, spring means tending to move theclutch plate into engagement with the brake means for its brakingposition, a magnetic coil disposed when energized to move the clutchplate into its position of operatively connecting the motor with thesprocket against the action of the spring means, and means to move theclutch plate into its neutral position for disconnection from thesprocket and rotation of the sprocket independently thereof.

3. A feed booster unit for ammunition feed belts, including a hollowsprocket, a motor therein, reduction gearing connecting the motor indriving relation with the sprocket, a magnetic clutch between the motorand said gearing for connecting the motor and gearing when said clutchis energized, and an electric circuit including said motor and saidmagnetic clutch arranged for simultaneous operation thereof.

4. An ammunition feed booster for machine guns including a sprocket andan electric circuit comprising an electric motor and magnetic clutchmeans, said clutch means being positioned between the motor and thesprocket whereby to actuate the clutch to drive the sprocket when saidcircuit is energized.

5. An ammunition feed booster for machine guns including a sprocket andan electric circuit comprising an electric motor and magnetic clutchmeans, said clutchmeans being positioned between the motor and thesprocket whereby to actuate the clutch to drive the sprocket when saidcircuit is energized, said clutch means including a braking element forstopping rotation of the sprocket upon deenergization of the circuit,and means for manually releasing the braking element so as to permitfree rotation of the sprocket while the motor is deenergized.

6. An ammunition feed booster for machine guns, comprising a hollowtubular sprocket, an electric motor within said sprocket and comprisingbearings for said sprocket, a motor shaft having a driving clutch plate,reduction driving gearing arranged for driving said sprocket, arotatable driving shaft for said gearing constructed and arranged forlongitudinal displacement and having a driven clutch plate thereonengageable with the driving clutch plate, a fixed brake plate, meansbiasing said driven plate in engagement with said brake plate, a powercircuit including said motor, and means operative when the circuit isenergized to displace said driving shaft and driven plate out ofengagement with the brake plate and into engagement with the drivingplate.

7. In combination, a gun firing means, an ammunition feed boosterincluding a sprocket, and an electric circuit comprising said gun firingmeans, an electric motor and magnetic clutch means, said clutch meansbeing positioned between the motor and the sprocket, whereby saidammunition feed booster and the firing means are actuated duringenergization of the circuit.

JAMES E. CHAPMAN. GEORGE A. BUSSIERE.

